Device for oiling and de-oiling compressed air

ABSTRACT

A device for oiling the fresh air and de-oiling the back flowing discharge air of a compressed air operable cylinder piston system having a reciprocatory piston comprising a housing which has a compressed air inlet and outlet and which has provided therein a control valve for the quantity of oil to be added to the compressed air to be passed through the compressed air outlet to the compressed air operable cylinder piston system. The compressed air outlet is through a tangential bore connected to an annular twist passage located above an annular chamber surrounding an inner chamber which has arranged therein a filter insert and communicates with the inlet through a bore. A check valve in the bore fully opens on fresh air passing from the air inlet to the outlet and is partially closable by the back flowing discharge air from the system.

United States Patent Scharfen et al.

Filed: June 3, 1974 Appl. No.: 475,806

Assignee:

Foreign Application Priority Data June 1, 1973 Germany 2327940 U.S. Cl. 184/55 A; 184/6.26 Int. Cl. F16n 7/32 Field of Search 184/55 R, 55 A, 18, 6.8, l84/6.l7, 6.26, 56 R, 56 A, 57, 58, 59, 6.21, 6.22, 6.23, 6.24, 7 F, 7 D

References Cited UNITED STATES PATENTS l/l949 Walters 184/55 A air a era/e a 6 Awe/- June 24, 1975 Primary E.raminerRichard C. Pinkham Assistant E.raminer-Arnold W. Kramer Attorney, Agent, or Firm-Walter Becker [57] ABSTRACT A device for oiling the fresh air and de-oiling the back flowing discharge air of a compressed air operable cylinder piston system having a reciprocatory piston comprising a housing which has a compressed air inlet and outlet and which has provided therein a control valve for the quantity of oil to be added to the compressed air to be passed through the compressed air outlet to the compressed air operable cylinder piston system. The compressed air outlet is through a tangential bore connected to an annular twist passage located above an annular chamber surrounding an inner chamber which has arranged therein a filter insert and communicates with the inlet through a bore. A check valve in the bore fully opens on fresh air passing from the air inlet to the outlet and is partially closable by the back flowing discharge air from the system.

5 Claims, 2 Drawing Figures 1 DEVlCE FOR OILING AND DE-OILING COMPRESSED AIR The present invention relates to a device for oiling and de-oiling compressed air for actuating compressed air operated cylinders with reciprocable piston and with a housing which contains the compressed air inlet and outlet and also contains a control valve for the quantity of oil to be added and furthermore contains a mixing chamber for atomizing the oil that is withdrawn from a storage container through a standpipe or riser.

Devices of the just mentioned type are known which are customarily designated as oilers. They are arranged either in the feeding line for the compressed air to a four-way valve controlling the compressed air cylinder or they are provided between the four'way valve and the connection of the compressed air cylinder which is located on the connecting rod side. While in the first mentioned instance the major portion of the oil contained in the air-oil mixture is precipitated already in the four-way valve and by means of the discharge air coming from the compressed air cylinder is blown into the atmosphere, with the arrangement of the oiler between the four-way valve and the compressed air cylinder. the proportion of the oil passing into the compressed air cylinder increases.

All heretofore known devices for oiling and de-oiling compressed air for actuating compressed air cylinders with reciprocable piston have the drawback that in view of the fact that the incoming fresh air due to the pressure build-up occurring during the actuation of the piston has a lower flow velocity than the discharge air flowing into the atmosphere, a considerable portion of the oil contained in the air-oil mixture does not pass into the compressed air cylinder but is deposited already in the feeding line. The oil thus deposited in the feeding line will then by the discharge air which at high velocity flows back, be drawn through the four-way valve into the atmosphere. Here the oil which was actually intended for the compressed air cylinder will contribute to considerable pollution of the environment.

It is, therefore. an object of the present invention so to improve the heretofore known devices for oiling and de-oiling. compressed air that the major portion of the oil conveyed through the control valve will actually reach the compressed air cylinder and the back flowing discharge air will be de-oiled with the exception of a negligible, small quantity thereof.

It is another object of the present invention to provide an arrangement as set forth above which will bring about a structural simplification of the device for oiling and dc-oiling compressed air.

These and other objects and advantages of the invention will appear more clearly from the following specification in connection with the accompanying drawing, in which:

FIG. 1 is a longitudinal section through a device according to the invention.

FIG. 2 represents a horizontal cross section taken along the line lI-Il of FIG. 1.

The device according to the present invention is characterized primarily in that the outlet connection connected to the compressed air cylinder is through a tangential bore connected to an annular twist passage which is located above an annular chamber cylinder surrounding an inner chamber which latter includes a filter insert and is connected to the inlet connection for fresh air through a bore, the cross section of which is adapted by means of a check valve partially to be closed by the discharge air flowing therethrough.

Due to this design. the de-oiling of the discharge air is effected primarily by a centrifugal force which is cre ated by the twist and which throws the oil onto the outer wall of the annular chamber, and secondarily by moistening the surface of the filter insert whereby also the oil mist will be separated which remains in the dis charge air after separation by centrifugal force. Inasmuch as the inner chamber which receives the filter insert is acted upon successively by discharge air and fresh air, an automatic cleaning of the filter insert is effected by the fresh air passing therethrough so that even with continuous use the separating power will not decrease. The compressed air to be intermixed with oil will in this way already in the inner chamber be moistened with oil droplets coming from the filter insert so that the mixing chamber proper will instead of receiving fresh air be fed already with an oil containing mixture. By closing a portion of the return flow cross section for the discharge air, a reduction in the return flow velocity will be obtained so that the transport of the oil mist to the compressed air cylinder will not be impeded, which transport pulsates in view of the periodi cal change in direction.

According to a preferred embodiment of the present invention, the annular chamber and the inner chamber are formed by an insert which is arranged below the twist passage. This insert may according to the invention be provided with at least one twist blade ring extending into the annular chamber and with at least one partition provided with passage bores and located within the region of the inner chamber so that the twisting effect as well as the throttling effect upon the back flowing discharge air will be increased.

if the device according to the invention is equipped with a sight glass for the stored oil which sight glass is arranged directly below the housing. while the riser is immersed into the stored oil, the insert with its filter insert may according to a further feature of the invention be slipped upon the riser arranged in the sight glass and may be held by a pressure or impact cone (Prallkegel) which prevents a swirling action of the oil and brings about a deviation of the air flowing between the annular chamber and the inner chamber.

Referring now to the drawing in detail. the device which is built in between the connection on the piston rod side of a compressed air cylinder and the pertaining four-way valve comprises a housing 1 which is equipped with an inlet connection 1a for the fresh air coming from the four-way valve, and is furthermore equipped with an outlet connection lb for the conduit conveying compressed air to the compressed air cylinder. Furthermore, a control valve 2 is arranged in the housing 1, which valve according to the specific showing in the drawing has a nozzle needle extending into a bore of the housing 1 and adjustable in a nut serving as stuffing box. The bore which is variable as to its cross section by the nozzle needle of the control valve 2 is provided with a riser 3 which immerses into the stored oil to be atomized. This oil supply is with the specific embodiment shown in the drawing contained in a sight glass 5 which consists of transparent material. preferably glass, said sight glass 5 being screwed onto the housing 1 from below.

The oil which is drawn in through the riser 3 and the quantity thereof passing through the riser per time unit. is controlled by the control valve 2 and through additional bores in housing 1 flows into a sight glass 4 which likewise consists of transparent material. preferably synthetic material. In the sight glass 4 there can be recognized the quantity of the oil which is variable by the control valve 2. because the oil drops from above into an atomizing nozzle 4a which extends into a mixing chamber 12. This mixing chamber It is with the illustrated embodiment designed adjacent to the outlet con nection lb and is located in the housing 1.

In the lower portion of the housing I there is provided a twist passage ld which through a tangential bore 1c communicates with the outlet connection 1/). Whereas the outer wall of the twist passage la is extended by the inner wall of the sight glass 5, the extension ofthe inner wall of the twist passage la is effected by an insert 6 which is connected to the housing I from below. This insert 6 which with the specific emhodi ment shown comprises two sections preferably of synthetic material, forms an annular chamber 11 below the twist passage 1c. This annular chamber 11 surrounds the inner chamber 12 ofthe insert 6 which inner cham her is provided with two partitions 6!) having passages 6r thercthrough.

The insert 6 which is provided with twist blade rings 61: extending into the annular chamber 11 is held on the riser 3 by a pressure impact cone 7. The communication between the inner chamber 12 and the inlet connection 1a is effected by two bores 8 one of which is adapted to be closed by a check valve 9 when discharge air flows out ofthe inner chamber 12 into the inlet connection la. in FIG. 2. the flap of the check valve 9 is indicated by a dot-dash line. In the interior of the insert 6 there is provided a filter insert 10 which preferably consists of sinter metal.

For removing the oil from the oil containing discharge air entering the outlet connection lb. said discharge air is through the tangential bore 10 conveyed into the twist passage 1d. The twist imparted in this way upon the discharge air brings about that the major por tion of the oil contained in the discharge air is separated and deposited on the outer wall of the twist passage Id and the adjacent annular chamber 11 in view of the centrifugal force. The separated oil runs down along the walls of the sight glass into the oil supply. The separating effect by centrifugal force is aided by the twist blade rings 6a of the insert 6 which extend into the annular chamber 11. As soon as the discharge air passes through the annular chamber 1]. it passes onto the impact cone 7 which guides the discharge air through the passage bores 6c into the inner chamber 12. Here the discharge air must pass through the filter insert of sinter metal. This filter insert 10 brings about the separation ofthe oil mist still in the discharge air which oil mist gets caught on and by the porous material of the filter insert 10. The discharge air from which the oil has been removed with the exception of a negligible. small portion of oil which discharge air is quieted by the second partition 6b of the insert 6, and now passes through the bore 8 which is not closed y the check valve 9, into the inlet connection In and from here through the non-illustrated founway valve into the atmosphere The fresh air which, following the reversal of the di rection of movement of the compressed air cylinder has been drawn in passes through the inlet connection la and both bores 8 into the inner chamber 12. During the passage of the fresh air through the filter insert 10, the fresh air picks up the finest oil particles in the filter 10 so that already a kind of pre-mixture is formed. This pre'mixture which passes out of passage bores 60 of the lowermost partition 61) of insert 6 is by the impact cone 7 deviated into the annular chamber ll without said prcniixture impacting upon the oil level below the impact cone 7. From the annular chamber 11 the air-oil mixture passes through the twist passage 1d and the tangential bore 1c into the mixing chamber le.

Due to the velocity of the fresh air which flows through the mixing chamber 1e and is already enriched with oil mist. a certain quantity of oil is through the riser 3 and sight glass 4 carried or drawn along, said quantity of oil being variably by adjusting the control valve 2. This quantity of oil drawn along is visible in the sight glass 4. The oil drops downwardly into the atomizing nozzle 40. the exit opening of which points in the direction toward the outlet connection 11). In this way. a further enrichment of the air-oil mixture with oil is effected in the mixing chamber 1e prior to the fresh air being conveyed to the compressed air cylinder.

it is, of course. to be understood that the present invention is. by no means. limited to the specific showing in the drawing but also comprises any modifications within the scope of the appended claims.

What we claim is:

l. A device for oiling and de-oiling compressed air for compressed air operated cylinder-piston systems with reversible piston movement. which includes: housing means having compressed air inlet and means for connection to a supply of fresh air and also having compressed air outlet means for connection to a compressed air operable cylinderpiston system with reversible piston movement, and oil reservoir connected to said housing means for receiving and storing oil, riser means extending from the inside of said reservoir to said housing means. said housing means being provided with passage means communicating with said riser means. control valve means associated with said passage means for selectively varying the free cross section thereof to thereby control the quantity of oil drawn per time unit into said passage means through said riser means. said housing means also comprising a mixing chamber. atomizing nozzle means communicating on one hand with said control valve means and on the other hand with said mixing chamber. that side of said housing means which faces said oil reservoir being provided with annular twist passage means open toward the interior of said oil reservoir, said housing means also being provided with tangential bore means effecting communication between said twist passage means and said mixing chamber, and thereby said outlet means, insert means arranged within said oil reservoir and connected to that side of said housing means which has said twist passage means provided therein, said insert means comprising an annular wall surrounding said riser means and having its outside surface together with the inner wall of said oil reservoir define annular chamfier rncans communicating with said twist passage means. the inner wall surface of said annular wall defining an inner chamber with perforated bottom and intermediate walls. filter means inserted in said inner chamher so that fluid passing through the perforations of said bottom wall must pass through said filter prior to passing through the perforations of said intermediate wall, conduit means for communication of said inner chamber with said inlet means. and check valve means associated with said conduit means and adapted. by back flowing discharge air of said system to be discharged through said conduit means to partially close said conduit means and said check valve means further adapted to fully open said conduit means in response to entry of fresh air through said inlet means.

2. A device according to claim 1, which includes a sight glass interposed between and communicating with said atomizing nozzle means and said control valve means.

3. A device according to claim 1. in which saidannumeans. 

1. A device for oiling and de-oiling compressed air for compressed air operated cylinder-piston systems with reversible piston movement, which includes: housing means having compressed air inlet and means for connection to a supply of fresh air and also having compressed air outlet means for connection to a compressed air operable cylinder-piston system with reversible piston movement, and oil reservoir connected to said housing means for receiving and storing oil, riser means extending from the inside of said reservoir to said housing means, said housing means being provided with passage means communicating with said riser means, control valve means associated with said passage means for selectively varying the free cross section thereof to thereby control the quantity of oil drawn per time unit into said passage means through said riser means, said housing means also comprising a mixing chamber, atomizing nozzle means communicating on one hand with said control valve means and on the other hand with said mixing chamber, that side of said housing means which faces said oil reservoir being provided with annular twist passage means open toward the interior of said oil reservoir, said housing means also being provided with tangential bore means effecting communication between said twist passage means and said mixing chamber, and thereby said outlet means, insert means arranged within said oil reservoir and connected to that side of said housing means which has said twist passage means provided therein, said insert means comprising an annular wall surrounding said riser means and having its outside surface together with the inner wall of said oil reservoir define annular chamber means communicating with said twist passage means, the inner wall surface of said annular wall defining an inner chamber with perforated bottom and intermediate walls, filter means inserted in said inner chamber so that fluid passing through the perforations of said bottom wall must pass through said filter prior to passing through the perforations of said intermediate wall, conduit means for communication of said inner chamber with said inlet means, and check valve means associated with said conduit means and adapted, By back flowing discharge air of said system to be discharged through said conduit means to partially close said conduit means and said check valve means further adapted to fully open said conduit means in response to entry of fresh air through said inlet means.
 2. A device according to claim 1, which includes a sight glass interposed between and communicating with said atomizing nozzle means and said control valve means.
 3. A device according to claim 1, in which said annular chamber means and said inner chamber are formed by said insert means, said insert means being arranged below said twist passage means.
 4. A device according to claim 1, in which said insert means is provided with at least one twist blade ring extending into said annular chamber means, and in which the perforations of said intermediate wall are located within the region of said inner chamber.
 5. A device according to claim 1, which includes an impact cone arranged below said insert means and located on said riser means for supporting said insert means. 